Conventional boilers utilise a fuel such as oil or gas which is generally fed to a burner unit which issues a flame from one or more nozzles, which flame is directed to be incident on one or more thermally conductive, usually metal, walls of the boiler in order to directly heat the walls of the boiler, which in turn heats a supply of water located within the boiler which may then be fed to a hot water supply, for example a domestic hot water supply consisting of a number of radiators and an immersion tank or the like. This conventional type of boiler includes a relatively small supply of water surrounding the combustion chamber, which thus has a relatively low thermal mass with little heat retention capability when the boiler is not operational.
In addition, such conventional boilers have a fixed and relatively limited hot water output, beyond which one or more additional boilers may be required.
It is therefore an object of the present invention to overcome the above-mentioned shortcomings of the prior art.